I am not sure the analogies are appropriate.

There is no elasticity in the leg cf a pole-vaulters pole.

The pendulum is a special case where gravity 'appears' to affect horizontal motion, but actually doesn't - the movement of the pendulum is not really horizontal - its circular - and it works through the vertical component.

Also when the pendulum is at maximum height the (pseudo)horizontal force is at it's maximum, the opposite situation to dancing.

To me the situation here (at the the top of swing in dancing) doesnt really have a geometry that couples the horizontal and the vertical.

"There is no elasticity in the leg cf a pole-vaulters pole."

You don't need elasticity for it to work over a limited range of angles, especially since we can bend our knee to smooth things out.

Is there any elasticity when a car coasts up a hill, slowing down?

"The pendulum is a special case where gravity 'appears' to affect horizontal motion, but actually doesn't - the movement of the pendulum is not really horizontal - its circular - and it works through the vertical component."

No one said the movement was purely horizontal, however there is most certainly a horizontal component of movement. And this is ultimately produced by the force of gravity acting through the geometry of the support situation. The horizontal accelerateions come from the same "normal force not vertical" situation as all of the other examples.

"Also when the pendulum is at maximum height the (pseudo)horizontal force is at it's maximum, the opposite situation to dancing."

No, it's the same as in dancing. The path of a waltz dancer and a pendulum blob are very comparable. When you are down, you are moving quickly with little change in horizontal speed, when you are up you are moving slowly with a lot of change of horzintal speed, as you'll slow to a stop and then re-accelerate. Just as a pendulum bob would. Though in waltz the radius of our upwsing is greater than the radius of our downswing - the model still works, when we consider the up and down separately we find they still match at the points where they join.

"To me the situation here (at the the top of swing in dancing) doesnt really have a geometry that couples the horizontal and the vertical."

Lock your legs rigid at the top of waltz rise and let yourself loose balance. You'll fall over, as and you fall you will accelerate horizontally (or simply stand a broom on end and let go of it). Of course in dancing we modulate this to make a more curved path, using amongst other things bend in our legs.

I was thinking about this more after I replied last night. And I can see now there is a horizontal component both in the bob and coming down from the top of the swing in waltz. I guess the coupling comes from bends in the legs and ankles which exist even at maximum height. So I can see how you get horizontal movement from gravity at the end of 3.

But I am not sure how you get up to maximum height just from horizontal movement and the geometry, or how gravity would slow down your horizontal movement during the rising phase. Surely the restoring force going up would be in the same direction as on going down (like in a bob) but in this case we need to to generate horizontal movement in one direction (not back and fourth like in a bob).

Surely to get rise you need to put energy in there somewhere as well as and in addition to generating swing on step 1.

I guess the relevance of all this is how much effort do you need to make to get rise and fall (and indeed horizontal movement). How much of it is natural ie coming by just letting youself fall and how much comes from using your muscles. Is fall just fall or is it controlled lowering ?

You obviously have thought about biomechanics of dance technique quite a lot. I was wondering if you know of any good references on the subject.

Interested. Google Luca and Lorain Waltz Demo or Foxtrot Demo and copy.We do have controlled rising and also control to lower.Both of our feet are on the ground. Nothing to do with a pole vaulter who uses a flexible pole and becomes airborne. I think the question that needs to be asked is. Is the rise to the full height in the Foxtrot obtained quicker than it is in the Waltz. It should be if you rise at the end of step one compared to commence to rise at the end of step one. Because Luca is dancing to much slower music than normal it is possible to get a better picture of what he is doing. Then go to Marcus Hilton Basic Waltz and Basic Foxtrot. You will see he dances with exactly the same technique but to a faster tempo.
Remember that story in ancient Greece how these professors and learned men argued for hours on how many teeth there were in a horses mouth when one bright student said why don't we just go to the stable and count them.
Following this advice. Why don't one or better still both. It can be done with a digital camera. With the camera on video look at both the Waltz and the Foxtrot and compare and ask yourself is there any differnce in the height, looking at the feet, between the two dances. Now we have gone to the stable.

Polished.

I take your point. But the video won't tell you how these effects are achieved,or not easily anyway.

Interested. Imagine the dancer has writen his phone number on the instep of the shoe underneath. Could you read it. I've done this to my shoes just in case I looose them any time.
I've put this on a few times. At the time that the feet are both under the body I would defy you or anybody to tell if you freeze frame which dance they are doing Waltz or Foxtrot.. Look at the end of step two in the Foxtrot in a Reverse Turn and step three in the Waltz. In both cases the feet are side by side. Are they the same hieght or are they not. Could you honestly say you would bet a weeks pay on which was which.

I agree the heights are similar in the two dances when freezeframed at a particular point. But that was last week's question. The issue now more about more changes in height between steps.

Interested. At last somebody who can believe their own eyes and isn't frighted to say so.
In a Foxtrot the lowering isn't verticle. In the Waltz when there is to be a lowering it is more often than not vertical. There are steps in the Waltz which are actually Foxtrot steps. In that case the lowering is as in a Foxtrot. There will always be exceptions to the rule. The Double Reverse Spin is used in all three of the Swing dances and requires Verticle lowering. That would include being down at the beginning as well as the end. If in the Foxtrot the step before was a Feather. I would be inclined to lower vertical Lest the partner gets push onto the heel turn.
I doubt if anybody can give an answer, there are more angles than on a cut diamond. Think of this and also look for yourself. On a backward step in the Foxtrot the lady bends the knee to the front at the same time extends the moving leg onto the toe. She will not lower untill the moving foot arrives under the body. but the man has already got his foot flat on the floor( as the book says at the extent of the stride the man will lower the ball to the floor imediately ) . Anybody who doesn't think so go and look for yourself. This is how the man is able to go past the lady on the third step of a Feather and change her position in relation to the room. Call it rotation if you like In other words the man is moving and for a fraction the lady makes room for the man allowing him space to occupy.Then they both come into a neutral position ready for the next step. So is the lady lowering more verticle than the man who decended on a slight slope, if I can call it that, but earlier than the lady. This is something else to look for. For those who don't understand how we rotate around each other. Think of a dot on a saucer and one for the lady. Rotate the saucer clockwise a little. The dot is still in the same places on the saucer. That is rotation.To make it harder we have CBMP involved thats why I wrote. I doubt if anybody can give an answer. Good Luck

Give an answer to what? I don't see a single question mark in your post.

Why do you use two different spellings for "vertical"?

When used as relative pronouns, "that" and "this" require clear antecedents.

This post is just another example of the jumbled, incoherent, thoughtless nonsense with which you regularly assault the other users of this forum.

Your refusal to take the time to post well written responses clearly indicates your contempt for the rest of us.

Perhaps your awful composition is an attempt to obscure the fact that you really know very little about ballroom dancing.

jj

I think the question was on the Foxtrot technique. Do we rise cradualy or do we rise quickly, Do we then travell on an horizontal plane and then gradualy lower or do we start to lower immediately after we reach our full height. Or do we use both techniques depending on the movement being used. Why do low grade medal dancers and Social Dancers look so unteresting to watch.Most don't seem to be aware that the partner is not doing the exact opposite of each other.So that even you will understand on the very first steps if it is a Natural in the Waltz or the first of a Feather Step in the Foxtrot. Both couples do not rise at the same time. If there is rise the person on the outside starts to rise first. The person on the inside will follow. On the second half of the Natural the roles are reversed.The Follower becomes the Leader. I ask the question. On the First and second step of the Feather Step. Does the man push up from a bent knee as the second step is taken.Is the Right heel off the floor coming from a toe to a toe. You'd be surprised how many don't get any rise at all. Before answering you might take a look at Luca and Lorain Foxtrot Demo and tell us if you think his rise is more vertical than horizontal. Bear that in mind the next time you are dancing and see , that's if you can see, the difference and how uninteresting it can looks. Flat as a tack.
P.S. What is a pronoun. And what is a antecedents. Who needs them anyway.
Of one who can walk with beggars and Kings and still retain the common touch. I'm with Humpty Dumpty who says that man should rule the words and not the words rule the man. Cheers